In posting my [comment](https://interpersonal.stackexchange.com/users/2308/wayne-werner) I just had a rather interesting idea for you.

Simply treat the baby as if it were any other human being that your co-worker brought to work. "Hello, John/Suzie/Starlord, pleased to make your acquaintance." You can shake their tiny hand, if that feels natural to you. If said with a smile, then it's unlikely to offend anyone, and even if everyone is into the "goo goo gah gah" talk, maybe they'll find your alternative approach amusing.